Semiconductor processing techniques are well known for manufacturing modern integrated circuits. A typical procedure in the manufacturing process includes photolithography, which involves passing light through a reticle (also referred to as a mask) to expose a layer's image for one or more die on a wafer. The wafer is “stepped” or moved and the photolithographic process repeated until the pattern of the reticle has been replicated on all of the die on the wafer (e.g., a step-and-repeat process performed by a stepper machine).
One drawback of a conventional photolithographic process, such as with die patterning performed using a single-stepped reticle set exposure, is that it is not possible to provide a unique identification for each die on the wafer. This is because the same reticle is exposed in multiple locations and results in the same pattern at each location (i.e., each die will have approximately an identical pattern at the end of the photolithographic process). Being able to uniquely identify each die on a wafer, even after the die have been separated from the wafer, may provide certain advantages, such as for example in terms of yield analysis and tracking of the die during and after the test, assembly, and packaging process. As a result, there is a need for improved semiconductor processing techniques.